distiller is available in Adobe Professional 6 and above or Adobe Distiller 5.
Sridhar. did you try killing distiller service in task manager before killing firefox.
Kill all Actobat services even acrobat_tray and all. Restart Adobe.
I use Adobe Professional and similar kind of errors come when Adobe services are all closed. On first instance of trying to print or save as pdf error comes giving no resul but starting the Adobe services. And then when I give for second try the pdf gets created.
This is my personal experience.
For you I can also say firefox ges hanged when you try to create pdf from it, and hence not letting distiller to work. I would suggest you to open the page in IE and then save as PDF from there. I do not have much experience of Firefox troubleshooting, can say that easily because Firefox gets hanged on my system even with 2GB RAM, I am an Opera user, do not like crappy IE. And please guys do not comment my likings. I mentioned this just for the troubleshooting's sake.